1. Field of the Invention
The present invention relates to an image forming apparatus, such as a copier, a facsimile, a printer, a multifunctional machine at least having two functions of these apparatuses, etc.
2. Discussion of the Background Art
A sheet internally ejecting type image forming apparatus, in which an image reading unit is mounted above an image printing unit at a prescribed interval, is well-known. Also well-known is an upper cover member that supports an image reading device and is upwardly swingable to allow accessing to the inside of the image printing section and maintenance or replacement of the consumables or the like. In such an image forming apparatus, when an operation section is regarded as a front side and the upper cover member swings around a rotational shaft arranged at the rear side of the apparatus, the front side of the apparatus is open, whereby maintenance or the like becomes convenient. Similarly, a platen cover provided to the image reading device so as to depress an original document also swings in the same direction as the upper cover member.
In such an image forming apparatus, when the upper cover member is open in addition to the platen cover, the platen cover is largely open and possibly drops by its own gravity or bumps into surroundings. Because, the platen cover is integrally arranged above the upper cover.
Then, the Japanese Patent Registration No. 3, 644,376 proposes an image forming apparatus capable of preventing the upper cover and the platen cover from being simultaneously open using a lock device.
However, usability is not excellent. Because, a handle is used to switch from locking to unlocking of the platen cover vice versa. Further, since the handle is secured to a body at the time of the locking, rigidity of parts needs be increased expecting application of an unreasonable force.